Big Lake is a term used to refer to two of the five Great Lakes in North America. The first is Lake Erie, which is located on the border between the United States and Canada and is the fourth largest of the Great Lakes. It has an area of approximately 25, 700 square miles and is the shallowest of the Great Lakes. The second is Lake Ontario, which is located entirely within Canada and is the smallest of the five Great Lakes. It has an area of approximately 7, 340 square miles and is the most easterly of the Great Lakes.